Stress field variation related to fault interaction in a reverse oblique-slip fault: the Alhama de Murcia fault, Betic Cordillera, Spain

• Published in: Tectonophysics 2002-10, Vol.356 (4), p.291-305
• Main Author: Martı́nez-Dı́az, José J
• Format: Article
• Language: English
• Subjects: Alhama de Murcia fault; Betic Cordillera; Neotectonics; Stress fields; Stress inversion
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/S0040-1951(02)00400-6

The interpretation of kinematic data from microstructural observations has led many authors to propose a complex dynamic development for the eastern Betic Cordillera from the Late Miocene to the present in which different—and sometimes contradictory—stress fields explain the generation of the same structures. The main aim of this work is to determine whether the dynamic variability of the study area, observed during the neotectonic period, is coherent with a single regional stress field. The structure of the area was analysed through the detailed mapping of the Alhama de Murcia fault (AMF) and the associated structures. Further, microtectonic data from shear veins in an interaction zone between the main and secondary faults were studied by the stress inversion method of Reches [Tectonics 6 (1987) 849]. A hierarchy is proposed for stress fields and their interpretation with respect to the interaction between structures of different scales. Relative movements of fault-bounded blocks with different sizes produce this hierarchy. These movements depend on boundary conditions of blocks and their position relative to the Alhama fault zone. The study shows that adequate cartography and understanding the context of micro- and mesotectonic data is necessary for determining the dynamic significance of microtectonic data. The use of stress inversion methods without taking the local tectonic context into consideration can give rise to incorrect interpretations, incorrect processing of previous data, and extrapolations inappropriate at other scales.